DESCRIPTION: The goal of this research is to understand the molecular mechanisms of recently discovered metalloproteins responsible for copper-homeostasis, oxidative stress responses, metal ion transport and copper detoxification. The structure and mechanisms of several newly discovered copper proteins are being explored. Some of the metalloproteins targeted in this study have genetically defined roles in oxidative stress responses. Wilson's disease, copper transport and detoxification. These are fundamental studies that provide new insights into the chemistry of copper in living cells. Inorganic, biochemical and recently developed NMR methods from this laboratory are employed to study chemistry, structure, mechanism and biological function of three classes of small and heretofore uncharacterized copper binding motifs that are common to an increasing number of copper proteins involved in copper hemeostasis, oxidative stress and human disease. The experimental strategy focuses first on characterizing prototypical structures and spectroscopic properties of small copper proteins that exhibit the highly conserved motifs. The biological function of the ancestral motifs will be addressed in genetic studies of a Cu-resistance operon of E. coli. This plasmid-based operon contains seven genes which function in conjunction with chromosomal genes to maintain Cu-homeostasis under a wide range of extracellular copper concentrations.